var browser = false;
if (document.all && document.getElementById)
	browser = 'ie';
if (!document.all && document.getElementById)
	browser = 'ns6';
if (!document.all && !document.getElementById && document.layers)
	browser = false //'ns4';
if (navigator.userAgent.indexOf("Opera") > -1 && document.getElementById)
	browser = 'opera';


var menuids = ['onas','nabidky'];
var submenuids = []; 
function showMenu(id,alturl)
	{
	if (id)
		{
		if (id.indexOf("sub") == 0)
			{
			hideMenus('sub');
			if (id == 'sub')
				return;
			}
			else
			{
			hideAllMenus();
			};
		}
		else
		{
		hideAllMenus();
		};
	if (browser == 'ie' && id)
		{
		document.all[id].filters[0].motion = "forward";
		document.all[id].style.visibility = 'visible';
		document.onmouseup = hideAllMenus;
		};
	if (browser == 'ns6' && id)
		{
		document.getElementById(id).style.visibility = 'visible';
		document.onmouseup = hideAllMenus;
		};
	if (browser == 'opera' && id)
		{
		document.getElementById(id).style.visibility = 'visible';
		document.onmouseup = hideAllMenus;
		};

	if (browser == 'ns4')
		{
		document.layers[id].visibility = 'visible';
		document.onmouseup = hideAllMenus;
		};

	if (!browser && alturl)
		{
		
		document.location = alturl;
		};
	};

function hideAllMenus()
	{
	hideMenus('sub');
	hideMenus();
	};

function hideMenus(s)
	{
	if (s == 'sub')
		m = submenuids;
		else
		m = menuids;
	for (var i=0; i<m.length; i++)
		{
		if (browser == 'ie')
			{
			document.all[m[i]].filters[0].motion = "reverse";
			document.all[m[i]].filters[0].apply();
			document.all[m[i]].style.visibility = 'hidden';
			document.all[m[i]].filters[0].play();
			};
		if (browser == 'ns6')
			{
			document.getElementById(m[i]).style.visibility = 'hidden';
			};
		if (browser == 'opera')
			{
			document.all[m[i]].style.visibility = 'hidden';
			};
		if (browser == 'ns4')
			{
			document.layers[m[i]].visibility = 'hidden';
			};
		};
	};